To get a where used list on test scripts available, here's what you can do... From the menu of transaction SECATTchoose Goto => Use of command. As the command choose "REF" and as Object in command fill in the test script you would like to see the where used list for. The use of your script in other test scripts as well as test confirurations is listed. Check out the other where-used options (commands) as well.
Alternatively: to find out in which masters a specific function is used (called via command REF) the table ECSCR_PAR can be used. Start transaction SE16 for table ECSCR_PAR- "Definition of eCATT Script Parameters and Variables" and fill in the function module name in field PREF_NAME2. As a result a list is displayed with all masters using this specific function.